Mouthpiece for a spirometer



FIG. 1 is a perspective view of a mouthpiece for a spirometer showing our new design;

FIG. 2 is a front view thereof;

FIG. 3 is a side elevational view thereof, the opposite side elevational view being identical thereto;

FIG. 4 is a back view thereof;

FIG. 5 is a top view thereof; and,

FIG. 6 is a bottom view thereof. 

The ornamental design for a mouthpiece for a spirometer, as shown and described. 